te crosses the western mountains at the Dragoman
Pass, continues through Sofia, Plovdiv, and down the Maritsa River
valley to Edirne and Istanbul in Turkey.

The rail network consists of about 3,775 miles of track, about 2,620 of
which were being operated in 1970. Of the portion in use, about 2,470
miles were standard gauge, and 150 were narrow gauge. Approximately 135
miles were double track, and a little more than 500 had been
electrified. Because of the terrain, the system has a large number of
bridges and tunnels and has been constructed with tighter curves and
steeper gradients than are allowed when terrain features are less
extreme. Most of the some 1,600 bridges are short, but at Ruse, where
the Danube is crossed, the river is 1-1/2 miles wide. Most of the
approximately 175 tunnels are also short. One is 3-1/2 miles in length,
but they total only about thirty miles (see fig. 4).

Route mileage is adequate to meet the requirements of the country. It
will probably not be expanded further; shorter spurs become uneconomic
and are abandoned as motor transport takes over short-haul traffic.
Programmed modernization includes improving roadbeds, ties, and track to
achieve a higher load-bearing capacity. Quantity installation of
continuously welded rail is also underway, and the busiest of the lines
are being electrified.

Although the system is adequate, performs its services reasonably well,
and continues to be the backbone of domestic transport, it suffers in
bare statistical comparisons with the other carriers. Highway transport
may carry a cargo to the rail station and get credit for a second
shipment when it moves the same goods from the train to its final
destination. Trucks also carry local freight more directly and much more
simply than railroads for short hauls. Ton mileage statistics of the
merchant marine are similarly misleading. Although the railroads remain
by far the most important domestic carrier, their share of total cargo
carried and their share of ton mileage continues to decrease (see table
2).

The railroads also continue to give way to motor vehicles in numbers of
passengers carried. Between 1960 and 1970 the situation changed
radically; on the earlier date the railroads carried more passengers
than buses did, but a decade later they carried hardly more than
one-third as many. In long-distance passenger travel, the railroads
remained the major carrier by a narrow margin in 1970, although the
d